<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <input value="cano" type="checkbox" onmouseover="document.getElementById('div1').style.display='block'"; onmouseout="div1.style.display='none'">
    <input value="cano" type="checkbox" onmouseover="document.getElementById('div1').style.display='block'"; onmouseout="div1.style.display='none'" onmouseover="document.getElementById('div1').className='div2'"; onmouseout="document.getElementById('div1').className='div1'">
    <div id="div1" class="div2" style="width: 200px; height: 100px; display: none ; background: gold;"></div>
    <div id="div2" class="div2" style="width: 400px; height: 300px; display: none ; background: green;"></div>
</body>
</html>